Improved screw-driver



i UNITED STATES PATENT OFFICE.

IMPROVED SCREW-DRIVER.

Specification forming part of Letters Patent No. 39,206, dated July 14,1863.

or turn-screw.

Similar letters of reference indicate corresponding parts in the severalfigures.

This invention consists in the employment or use of a bit or turn-screwand a shank, constructed and arranged in such a manner that the bit orturn-screw may be readily and rmly secured in the shank, and the formerrendered capable of being firmly secured or held in the slot of thescrew, so that the latter may be made to enter the wood or screwed intoit without the application of the hands to the screw. The bit orturn-screwis so constructed and arranged as to be reversible, one endbeing formed in the ordinary way, or like a common screw-driver orturn-screw, and the other end being constructed in a novel way, so as tobind in the slot of the screw, as hereinafter fully shown and described.

To enable those skilled in the art to fully understand and construct myinvention, I will proceed to describe it.

A represents a wooden handle, which has a metal shank, B, firmly securedin it. This shank is slotted longitudinally from its outer end inward acertain distance, and has a setscrew, C, passing transversely throughit, as shown clearly in Fig. 1. The shank B may be of 'cylindrical form,and it has a flat end, which is at right angles to its periphery, asshown clearly in Fig. l.

D represents the bit or turn-screw, one end, a, of which is formed inthe usual way, as shown clearly in Fig. et, and the opposite end isslotted longitudinally a certain distance so as to form two prongs, b b.On one side of each prong there is a shoulder or lateral projection, c,the projection of one paong being at one side of the bit, and the otherprojection at the opposite side, as shown more particularly in Fig. 4.At about the vcenter of the bit or turn-screw D there is made an ovalhole, d, and the slot e of the bit or turn-screw extends to this holecl. The prongs b b have a certain degree of elasticity, and when saidprongs are not acted upon by any extraneous force or power the ends ofthe prongs will be in line with each other, as shown in Fig. 4, and forman ordinary screwdriver. This end of the bit or turn-screw, however,operates widely different from an ordinary turn-screw, and it is used asfollows: The bit or turnscrew D is fitted in the slot of the shank B,the set-screw C passing through the hole din the turn-screw. The ends ofthe prongs b b are then tted in the slot f of the head g of the screw,and the head g is then adjusted in contact with the flat end of theshank, and the two parts of the shank clamped firmly against the sidesof the turn-screw by turning or screwing up the set-screw C. As the twoparts of the shank press against the projections c c, the prongs b bWill be thrown out of line with each other and thereby made to bindfirmly in the Vslotf, and hold the screw to the shank B. In Fig. 2 theends of the prongs b b are shown in line with each other, and out ofline with each other in Fig. 3. When the other end ofthe turn-screw isto be used, it is removed from the shank and re versed. By thisarrangement it will be seen that the screw may be lirmly secured to theshank B, and the screw may be made to enter the wood and screwed into itwithout applying the hands to the screw, and without the possibility ofthe turn-screw slipping out from the slot j'.

This invention may be used toadvantage with all kinds of screws whichare designed to be turned by a screw-driver, and is especially adaptedfor use with my improved screw provided with a dovetail slot, andformerly patented by me, the Letters Patent bearing date April 14, 1863.

Having thus described my invention, whatI claim as new, and desire tosecure by Letters Patent, is-

1. A screwdriver formed or composed of a shank, B, slottedlongitudinally and provided with a set-screw, C, and a detached orremovable bit or turn-screw, D, substantially as set forth.

2. Having the bit or turn-screw D provided with two prongs, b b, formedby slotting the bit or turn-screw longitudinally, and havingeach prongprovided with a. lateral projection, c, or an equivalent device orarrangement, s0 that the prongs will be thrown out of line with eachother by screwing up the setscrew C, and made to bind in the slotfof thescrew, substantially as herein described.

3. The reversible bit or turn-screw D, provided at one end with the twoelastic or yielding prongs b b, and at the other end with the ordinaryturn-screw a., so that either may be used es described.

J. A. AYRES.

Witnesses:

CHAs. C. SHULTAs, DAVID L. HUBBARD.

